Show all posts by user

Re: Wax printing - 11 years ago

Yes, I am fimiliar with them, I occasionaly search on auction sites to try and get one to play with, a friend did buy one some time ago, but I am not so lucky, I think they have a lot of potential for hacking, if you get your hands on one please post any info. Edit, Canon Colour Ink Jet printers I had one from the skip, the printheads were tiny, must be very rare now.

by johnrpm - General

Microsoft sells makerbots - 11 years ago

I hope they are happy together, I hold them both in the same regard.

by johnrpm - General

Re: Would you list your idle 3D printer online and request local prints? - 11 years ago

What value do you add to the transaction He obviously wants to offer a service to the community, and is not interested in making a profit, or being a middle man like Ebay making profits from each purchase and then on payments. Forgive my Cynicism, but life makes you that way sometimes.

by johnrpm - General

Re: 3D cement printer - 11 years ago

I am no expert on concrete, but various accelerators are available, chemicals, but they can adversly effect the final strength.

by johnrpm - General

Re: 3D cement printer - 11 years ago

Imagine a chain pulled up through a bucket of mortar, and compressed air blowing the mortar of the chain, the chain could be replaced with a strip having holes or a rotating disc with holes, this would give the advantage of DOD, although the dots may be large.

by johnrpm - General

Re: new 3D printer i'm going to follow from velleman - 11 years ago

I see that maplins will be selling the velleman kit

by johnrpm - General

Re: new 3D printer i'm going to follow from velleman - 11 years ago

Why not, everyone else is jumping on the band wagon, the velleman kits I have built use good componants and the boards are first class, I must admit i never expected velleman to jump in, but they are a respected company at least, who next?.

by johnrpm - General

Re: Making ABS powder suggestion - 11 years ago

diffraction of multiple lasers and the inverse Fourier transform to cure patterns at the nanoscale Would the particle size of the powder be the limiting factor???, This concept would not be suitable for all geometries of course, but it may be posible to use resins if something similar to splutter coating was used, a bit like a mistmaker creating a resin mist that drifts down.

by johnrpm - Powder Printing and Selective Laser Sintering

Re: Making ABS powder suggestion - 11 years ago

A concept I have had in mind for some time, imagine a post, the charged powder is attracted to it, energy, lasers, electron beam or whatever aranged similar to a tomography layout fuses the powder, with multple lasers acting in unison on multiple areas of the part. faster... I do not know more accurate... maybe it would be pure research, needing lots of time and effort.

by johnrpm - Powder Printing and Selective Laser Sintering

Re: Making ABS powder suggestion - 11 years ago

Elecrostatic... laser printer...laser...very fine layers....Elecrostatic. all the elements of a true 3d printer, not just layer by layer, but building in 3D.

by johnrpm - Powder Printing and Selective Laser Sintering

Re: DIY printhead - 11 years ago

something I intended doing but never had time, was have a peizo lighter unit or units, acting on a shim, similar to the origonal design on the wiki, but the lighter units could act on two faces or shims to get amplitude, and could go to a higher frequency, anyone up for it.

by johnrpm - Powder Printing and Selective Laser Sintering

Re: Amazing Piezoelectric Polyvinylidene Fluoride - 11 years ago

I imagine depositing in the normal way, then lifting the nozzle a little in order to stop bonding to the previous layer, and amending velocity a little to get the stretch, maybe stitch to the previous layer at regular intervals.

by johnrpm - Developers

Re: Need help with a toolhead for a working powder printer (focus) - 11 years ago

You have probably seen this, but if not its a bit old now but may be usefull, Adrian built a reprapable printhead with some instructions I think, but I have no plans to revisit the printhead, I go where my interest takes me, and its elsewhere at the moment, I did hope that others would follow up on it and improve it, but not so it seems. Just a thought, but what if you fired just one nozzle

by johnrpm - Powder Printing and Selective Laser Sintering

Re: Need help with a toolhead for a working powder printer (focus) - 11 years ago

Well done dragonnator on this build, I suppose you have already considered stripping out the printhead and rail from a cheap printer, that would give the posibility for colours eventualy.

by johnrpm - Powder Printing and Selective Laser Sintering

Re: Amazing Piezoelectric Polyvinylidene Fluoride - 11 years ago

Thanks MattMoses for unearthing the old posts, looks like I was wrong about no response, it would make a worthy project, but consume vast amounts of time, just a thought, but could the bead be stretched (as in the above info) during deposition?.

by johnrpm - Developers

Re: Amazing Piezoelectric Polyvinylidene Fluoride - 11 years ago

My post was at least a year ago, it should be there somewhere, It would not be a simple task, the electrodes would need to be at the melt point, and maybe at the platform, the cooling rate is fast so may not take poling well, also if poling is posible on the fly, it may produce the piezo material for the bead but not over the entire part, lots of work, but worth it, and at least for some time not

by johnrpm - Developers

Re: Amazing Piezoelectric Polyvinylidene Fluoride - 11 years ago

I proposed this ages ago, but I do not think I got one response, (I can't be bothered to find post) my understanding is that the polymer is held at about 100v whilst it cools to polerise it, my thoughts were to have electrodes on the nozzle and build sensors/ actuators directly.

by johnrpm - Developers

Re: New Polar-3D Printer/Mill/Scanner now in test - 11 years ago

Very nice concept, I have always felt that rotation is more efficient, but adds other complications, but as processing power has increased these complications are not the barrier they once were. This is a concept that I thought may be good for powderbed printers, but in a different configaration of course, well done, inovation still lives.

by johnrpm - Polar Machines, SCARA, Robot Arms

Re: Where to post? - 11 years ago

Good work Malden, it would be good to see what you have done, I had intended to do something similar but its good that you have taken this on, please put a link to it.

by johnrpm - Administration, Announcements, Policy

Re: Pen Plotter Shading - Help - 11 years ago

, the pencil is held much like a hand and rotates to overcome wear, I think I used DotG or some other free software and Mach3

by johnrpm - General

Re: Braille / Tactile Graphics.... - 11 years ago

I sent some emails to the institute for the blind ages ago with this in mind but never did get a reply.

by johnrpm - General

Re: Stratasys fdm 8000 retrofitting Arduino anyone - 11 years ago

I have both but would need to rummage around to find them.

by johnrpm - General

Re: pcduino - 11 years ago

If it could run linuxcnc it would be really usefull.

by johnrpm - Slic3r

Re: Let's reconsider... - 11 years ago

Let's reconsider..., what needs to be reconsidered, he has his opinion and you have yours.

by johnrpm - General

Re: 3D Metal Printer Projects? - 11 years ago

As Miso states, it depends on what you want as the end result, if low resolution is OK, then an idea I posted some years ago may be worth revisiting," ballbearings", a similar size as found in ballpoint pens, fused together by an arc, if you have seen pnuematic silencers the finished product could look similar to them, the power supply is relatively low tech and would not require exotic technolog

by johnrpm - General

Re: Most cost-efficient 3-D printers for school arts? - 11 years ago

The UP printer is popular with education, but not cheap.

by johnrpm - General

Re: awesome Kinect 3d real time scanning software check it out it auto makes STL files. - 11 years ago

roygpa, I had the same problem, but I downloaded the OLD VERSION of Skanect and it works, at least I can get some result with a used xbox Kinect bought from Ebay, not sure if OpenCL enabled gpu's are standard now or if its just for gaming type cards.

by johnrpm - 3D Scanners, Book Scanners, and Optics

Re: My wife just passed away. - 11 years ago

It happened to me some years ago, I know the place you are in and I still do not have the words to help. you are among friends, just take one day at a time.

by johnrpm - General

Re: Feature Request multiple extruder Z offset - 11 years ago

No problem, I shall solve it another way, but looking ahead to machines that have multiple abilities, cutting, placement, etc, some form of TLO will be needed.

by johnrpm - Slic3r

Re: Feature Request multiple extruder Z offset - 11 years ago

only thing i can think of is something that could switch hot ends.so you would only have 1 in at a time. i suppose you could also have your hot ends rotate some how. spot on dissidence, Its a robot arm with (at the moment 2 heads), still being built, but if its a problem I can write a parser for the gcode to solve my problem, but any format mentioned by dissidence would need it.

by johnrpm - Slic3r